package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.COMMON_FOLLOW_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private IUserService userService;
    @Override
    public Result isfllow(Long fllowUserID) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId).eq("follow_user_id", fllowUserID).count();
        return Result.ok(count>0);
    }

    /**
     * 实现关注某个用户的功能
     * @param followUserID
     * @param flag
     * @return
     */
    @Override
    public Result follow(Long followUserID, Boolean flag) {
        Long userId = UserHolder.getUser().getId();
        String FollowKey = COMMON_FOLLOW_KEY+userId;
        if(flag == true){
            // 要进行关注业务的操作
            Follow follow = new Follow();
            follow.setFollowUserId(followUserID);
            follow.setUserId(userId);
            boolean save = save(follow);
            if(flag){
                stringRedisTemplate.opsForSet().add(FollowKey,followUserID.toString());
            }

        }else{
            // 进行取消关注业务的操作
            boolean remove = remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", followUserID));
            if(remove){
                stringRedisTemplate.opsForSet().remove(FollowKey,followUserID.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result commonFollow(Long anotherID) {
        //1. 获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key1 = COMMON_FOLLOW_KEY + userId;
        String key2 = COMMON_FOLLOW_KEY + anotherID;

        // 2. 求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);
        if(intersect==null && intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }


        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());

        return Result.ok(users);

    }
}
